These are optional hollow carbon gear shafts for the M03, M04, and FF02 chassis cars. FEATURES: Features carbon fiber construction for lightweight performance. Transmits the motor power to the wheels efficiently. INCLUDES: One 20mm carbon gear shaft One 40mm carbon gear shaft REQUIRES: Eight 5x11mm bearings (can use DTXC1549) COMMENTS: The bearings are used in conjunction with the carbon gear shafts and transmission gears. The idler gear, spur gear, and counter gears are supported by these carbon gear shafts. These shafts have a outer diameter of 5mm. baw 11/07/02 ir/kh